Add remote cache for Gerrit branch builds

Change-Id: Idfc6f5a092e7f99a8c549b0422f3947e801092a1
diff --git a/jenkins/gerrit-bazel-test.sh b/jenkins/gerrit-bazel-test.sh
index 1ed014c..a5ad73e 100755
--- a/jenkins/gerrit-bazel-test.sh
+++ b/jenkins/gerrit-bazel-test.sh
@@ -24,7 +24,7 @@
     ;;
 esac
 
-export BAZEL_OPTS="$BAZEL_OPTS \
+export BAZEL_OPTS="$(echo $BAZEL_OPTS | xargs) \
                    --flaky_test_attempts 3 \
                    --test_timeout 3600 \
                    --test_tag_filters=-flaky"